Last updated 24 March 2024


Part One

Series Episode Number: 382

World Premiere: Sat 28 Dec 1974 - 5:35pm GMT [BBC One] (United Kingdom)
First Broadcast: Tue 26 Feb 1980 - 5:30pm CST [WTTW 11 Chicago]
Running Time: 24 minutes 11 seconds

10.80 Million (UK)

Appreciation Index: 53 (UK)

Chart Position: 25 () (UK)

Recorded on Tue 21 May 1974 in TC3



UNIT are called in when top secret plans and valuable equipment is stolen from high security establishments. The newly regenerated Doctor suggests that the thief may not be human.


Characters hide uncredited
Doctor WhoTom Baker
Sarah Jane SmithElisabeth Sladen
Harry SullivanIan Marter
Brigadier Lethbridge-StewartNicholas Courtney
Sergeant BentonJohn Levene
Miss WintersPatricia Maynard
RobotMichael Kilgarriff
Professor KettlewellEdward Burnham
JellicoeAlec LinsteadInfo
(extra)Allan Hinton (uncredited)
(extra)Bill Bingham (uncredited)
(extra)Brian Fellows (uncredited)
(extra)Christopher Carrington (uncredited)
(extra)Colin Hamilton (uncredited)
(extra)David Melbourne (uncredited)
(extra)David Parker (uncredited)
(extra)Douglas Read (uncredited)
(extra)Elizabeth Cassidy (uncredited)
(extra)Evan Ross (uncredited)
(extra)Fred Garratt (uncredited)
(extra)Gordon Wall (uncredited)
(extra)Jack Parker (uncredited)
(extra)Joe Phillips (uncredited)
RobotJohn East (uncredited)Info
(extra)John Scott Martin (uncredited)
(extra)Leslie Weekes (uncredited)
(extra)Mrs Wickett (uncredited)
(extra)Nigel Stevens (uncredited)
(extra)Norman Littlejohns (uncredited)
(extra)Pat Gorman (uncredited)
(extra)Peter Isley (uncredited)
(extra)Roger Squires (uncredited)
(extra)Steve Rivers (uncredited)
Doctor WhoJon Pertwee (uncredited)